Implanted devices are well suited for recording intracardiac electrical potentials (i.e., for example, electromyograms; EMG) because they are isolated from electrical signals from outside the body. The morphology of an EMG reflects local and global electrical activity of the heart. There has been a dramatic increase in the utilization of implantable cardioverter defibrillators (ICD's) and pacemakers and as a result, there is an abundance of EMG information available. However, few attempts have been made to extract information from the EMG's aside from the discrimination of supraventricular (SVT) and ventricular tachycardias (VT). One reason that these attempts have not been successful is due to the fact that the unknown and arbitrary orientation of the recording device prevents rapid interpretation by medical personnel.
What is needed is an electrocardiogram reconstruction technique using electrical potentials obtained from a device implanted within a patient.